Implement missing Math logarithm functions from ES6

jerry-core/ecma/builtin-objects/ecma-builtin-math.c

@@ -570,38 +570,22 @@ ecma_builtin_math_dispatch_routine (uint16_t builtin_routine_id, /**< built-in w
       }
       case ECMA_MATH_OBJECT_EXPM1:
       {
-#ifdef JERRY_LIBM_MATH_H
-        return ecma_raise_type_error (ECMA_ERR_MSG ("UNIMPLEMENTED: Math.expm1"));
-#else /* !JERRY_LIBM_MATH_H */
         x = DOUBLE_TO_ECMA_NUMBER_T (expm1 (x));
-#endif /* JERRY_LIBM_MATH_H */
         break;
       }
       case ECMA_MATH_OBJECT_LOG1P:
       {
-#ifdef JERRY_LIBM_MATH_H
-        return ecma_raise_type_error (ECMA_ERR_MSG ("UNIMPLEMENTED: Math.log1p"));
-#else /* !JERRY_LIBM_MATH_H */
         x = DOUBLE_TO_ECMA_NUMBER_T (log1p (x));
-#endif /* JERRY_LIBM_MATH_H */
         break;
       }
       case ECMA_MATH_OBJECT_LOG10:
       {
-#ifdef JERRY_LIBM_MATH_H
-        return ecma_raise_type_error (ECMA_ERR_MSG ("UNIMPLEMENTED: Math.log10"));
-#else /* !JERRY_LIBM_MATH_H */
         x = DOUBLE_TO_ECMA_NUMBER_T (log10 (x));
-#endif /* JERRY_LIBM_MATH_H */
         break;
       }
       case ECMA_MATH_OBJECT_LOG2:
       {
-#ifdef JERRY_LIBM_MATH_H
-        return ecma_raise_type_error (ECMA_ERR_MSG ("UNIMPLEMENTED: Math.log2"));
-#else /* !JERRY_LIBM_MATH_H */
         x = DOUBLE_TO_ECMA_NUMBER_T (log2 (x));
-#endif /* JERRY_LIBM_MATH_H */
         break;
       }
       case ECMA_MATH_OBJECT_SINH:

jerry-libm/expm1.c

@@ -0,0 +1,305 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is based on work under the following copyright and permission
+ * notice:
+ *
+ *     Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ *     Permission to use, copy, modify, and distribute this
+ *     software is freely granted, provided that this notice
+ *     is preserved.
+ *
+ *     @(#)s_expm1.c 5.1 93/09/24
+ */
+
+#include "jerry-libm-internal.h"
+
+/* expm1(x)
+ * Returns exp(x)-1, the exponential of x minus 1.
+ *
+ * Method
+ *   1. Argument reduction:
+ *  Given x, find r and integer k such that
+ *
+ *               x = k*ln2 + r,  |r| <= 0.5*ln2 ~ 0.34658
+ *
+ *      Here a correction term c will be computed to compensate
+ *  the error in r when rounded to a floating-point number.
+ *
+ *   2. Approximating expm1(r) by a special rational function on
+ *  the interval [0,0.34658]:
+ *  Since
+ *      r*(exp(r)+1)/(exp(r)-1) = 2+ r^2/6 - r^4/360 + ...
+ *  we define R1(r*r) by
+ *      r*(exp(r)+1)/(exp(r)-1) = 2+ r^2/6 * R1(r*r)
+ *  That is,
+ *      R1(r**2) = 6/r *((exp(r)+1)/(exp(r)-1) - 2/r)
+ *         = 6/r * ( 1 + 2.0*(1/(exp(r)-1) - 1/r))
+ *         = 1 - r^2/60 + r^4/2520 - r^6/100800 + ...
+ *      We use a special Reme algorithm on [0,0.347] to generate
+ *   a polynomial of degree 5 in r*r to approximate R1. The
+ *  maximum error of this polynomial approximation is bounded
+ *  by 2**-61. In other words,
+ *      R1(z) ~ 1.0 + Q1*z + Q2*z**2 + Q3*z**3 + Q4*z**4 + Q5*z**5
+ *  where   Q1  =  -1.6666666666666567384E-2,
+ *     Q2  =   3.9682539681370365873E-4,
+ *     Q3  =  -9.9206344733435987357E-6,
+ *     Q4  =   2.5051361420808517002E-7,
+ *     Q5  =  -6.2843505682382617102E-9;
+ *    z   =  r*r,
+ *  with error bounded by
+ *      |                  5           |     -61
+ *      | 1.0+Q1*z+...+Q5*z   -  R1(z) | <= 2
+ *      |                              |
+ *
+ *  expm1(r) = exp(r)-1 is then computed by the following
+ *   specific way which minimize the accumulation rounding error:
+ *                        2     3
+ *                        r     r    [ 3 - (R1 + R1*r/2)  ]
+ *        expm1(r) = r + --- + --- * [--------------------]
+ *                        2     2    [ 6 - r*(3 - R1*r/2) ]
+ *
+ *  To compensate the error in the argument reduction, we use
+ *    expm1(r+c) = expm1(r) + c + expm1(r)*c
+ *         ~ expm1(r) + c + r*c
+ *  Thus c+r*c will be added in as the correction terms for
+ *  expm1(r+c). Now rearrange the term to avoid optimization
+ *   screw up:
+ *                  (      2                                    2 )
+ *                  ({  ( r    [ R1 -  (3 - R1*r/2) ]  )  }    r  )
+ *   expm1(r+c)~r - ({r*(--- * [--------------------]-c)-c} - --- )
+ *                  ({  ( 2    [ 6 - r*(3 - R1*r/2) ]  )  }    2  )
+ *                  (                                             )
+ *
+ *       = r - E
+ *   3. Scale back to obtain expm1(x):
+ *  From step 1, we have
+ *     expm1(x) = either 2^k*[expm1(r)+1] - 1
+ *              = or     2^k*[expm1(r) + (1-2^-k)]
+ *   4. Implementation notes:
+ *  (A). To save one multiplication, we scale the coefficient Qi
+ *       to Qi*2^i, and replace z by (x^2)/2.
+ *  (B). To achieve maximum accuracy, we compute expm1(x) by
+ *    (i)   if x < -56*ln2, return -1.0, (raise inexact if x!=inf)
+ *    (ii)  if k=0, return r-E
+ *    (iii) if k=-1, return 0.5*(r-E)-0.5
+ *    (iv)  if k=1 if r < -0.25, return 2*((r+0.5)- E)
+ *                  else       return  1.0+2.0*(r-E);
+ *    (v)   if (k<-2||k>56) return 2^k(1-(E-r)) - 1 (or exp(x)-1)
+ *    (vi)  if k <= 20, return 2^k((1-2^-k)-(E-r)), else
+ *    (vii) return 2^k(1-((E+2^-k)-r))
+ *
+ * Special cases:
+ *  expm1(INF) is INF, expm1(NaN) is NaN;
+ *  expm1(-INF) is -1, and
+ *  for finite argument, only expm1(0)=0 is exact.
+ *
+ * Accuracy:
+ *  according to an error analysis, the error is always less than
+ *  1 ulp (unit in the last place).
+ *
+ * Misc. info.
+ *  For IEEE double
+ *      if x >  7.09782712893383973096e+02 then expm1(x) overflow
+ *
+ * Constants:
+ * The hexadecimal values are the intended ones for the following
+ * constants. The decimal values may be used, provided that the
+ * compiler will convert from decimal to binary accurately enough
+ * to produce the hexadecimal values shown.
+ */
+
+#define one 1.0
+#define huge 1.0e+300
+#define tiny 1.0e-300
+#define o_threshold 7.09782712893383973096e+02 /* 0x40862E42, 0xFEFA39EF */
+#define ln2_hi 6.93147180369123816490e-01      /* 0x3fe62e42, 0xfee00000 */
+#define ln2_lo 1.90821492927058770002e-10      /* 0x3dea39ef, 0x35793c76 */
+#define invln2 1.44269504088896338700e+00      /* 0x3ff71547, 0x652b82fe */
+
+/* Scaled Q's: Qn_here = 2**n * Qn_above, for R(2*z) where z = hxs = x*x/2: */
+#define Q1 -3.33333333333331316428e-02 /* BFA11111 111110F4 */
+#define Q2 1.58730158725481460165e-03  /* 3F5A01A0 19FE5585 */
+#define Q3 -7.93650757867487942473e-05 /* BF14CE19 9EAADBB7 */
+#define Q4 4.00821782732936239552e-06  /* 3ED0CFCA 86E65239 */
+#define Q5 -2.01099218183624371326e-07 /* BE8AFDB7 6E09C32D */
+
+double
+expm1 (double x)
+{
+  double y, hi, lo, c, e, hxs, hfx, r1;
+  double_accessor t, twopk;
+  int k, xsb;
+  unsigned int hx;
+
+  hx = __HI (x);
+  xsb = hx & 0x80000000; /* sign bit of x */
+  hx &= 0x7fffffff;      /* high word of |x| */
+
+  /* filter out huge and non-finite argument */
+  if (hx >= 0x4043687A)
+  {
+    /* if |x|>=56*ln2 */
+    if (hx >= 0x40862E42)
+    {
+      /* if |x|>=709.78... */
+      if (hx >= 0x7ff00000)
+      {
+        unsigned int low;
+        low = __LO (x);
+        if (((hx & 0xfffff) | low) != 0)
+        {
+          /* NaN */
+          return x + x;
+        }
+        else
+        {
+          /* exp(+-inf)-1={inf,-1} */
+          return (xsb == 0) ? x : -1.0;
+        }
+      }
+      if (x > o_threshold)
+      {
+        /* overflow */
+        return huge * huge;
+      }
+    }
+    if (xsb != 0)
+    {
+      /* x < -56*ln2, return -1.0 with inexact */
+      if (x + tiny < 0.0) /* raise inexact */
+      {
+        /* return -1 */
+        return tiny - one;
+      }
+    }
+  }
+
+  /* argument reduction */
+  if (hx > 0x3fd62e42)
+  {
+    /* if  |x| > 0.5 ln2 */
+    if (hx < 0x3FF0A2B2)
+    {
+      /* and |x| < 1.5 ln2 */
+      if (xsb == 0)
+      {
+        hi = x - ln2_hi;
+        lo = ln2_lo;
+        k = 1;
+      }
+      else
+      {
+        hi = x + ln2_hi;
+        lo = -ln2_lo;
+        k = -1;
+      }
+    }
+    else
+    {
+      k = (int) (invln2 * x + ((xsb == 0) ? 0.5 : -0.5));
+      t.dbl = k;
+      hi = x - t.dbl * ln2_hi; /* t*ln2_hi is exact here */
+      lo = t.dbl * ln2_lo;
+    }
+    x = hi - lo;
+    c = (hi - x) - lo;
+  }
+  else if (hx < 0x3c900000)
+  {
+    /* when |x|<2**-54, return x */
+    return x;
+  }
+  else
+  {
+    k = 0;
+  }
+
+  /* x is now in primary range */
+  hfx = 0.5 * x;
+  hxs = x * hfx;
+  r1 = one + hxs * (Q1 + hxs * (Q2 + hxs * (Q3 + hxs * (Q4 + hxs * Q5))));
+  t.dbl = 3.0 - r1 * hfx;
+  e = hxs * ((r1 - t.dbl) / (6.0 - x * t.dbl));
+  if (k == 0)
+  {
+    /* c is 0 */
+    return x - (x * e - hxs);
+  }
+  else
+  {
+    twopk.as_int.hi = 0x3ff00000 + ((unsigned int) k << 20); /* 2^k */
+    twopk.as_int.lo = 0;
+    e = (x * (e - c) - c);
+    e -= hxs;
+    if (k == -1)
+    {
+      return 0.5 * (x - e) - 0.5;
+    }
+    if (k == 1)
+    {
+      if (x < -0.25)
+      {
+        return -2.0 * (e - (x + 0.5));
+      }
+      else
+      {
+        return one + 2.0 * (x - e);
+      }
+    }
+    if ((k <= -2) || (k > 56))
+    {
+      /* suffice to return exp(x)-1 */
+      y = one - (e - x);
+      if (k == 1024)
+      {
+        y = y * 2.0 * 0x1p1023;
+      }
+      else
+      {
+        y = y * twopk.dbl;
+      }
+      return y - one;
+    }
+    t.dbl = one;
+    if (k < 20)
+    {
+      t.as_int.hi = (0x3ff00000 - (0x200000 >> k)); /* t=1-2^-k */
+      y = t.dbl - (e - x);
+      y = y * twopk.dbl;
+    }
+    else
+    {
+      t.as_int.hi = ((0x3ff - k) << 20); /* 2^-k */
+      y = x - (e + t.dbl);
+      y += one;
+      y = y * twopk.dbl;
+    }
+  }
+  return y;
+} /* expm1 */
+
+#undef one
+#undef huge
+#undef tiny
+#undef o_threshold
+#undef ln2_hi
+#undef ln2_lo
+#undef invln2
+#undef Q1
+#undef Q2
+#undef Q3
+#undef Q4
+#undef Q5

jerry-libm/include/math.h

@@ -58,7 +58,11 @@ double atan2 (double, double);
 
 /* Exponential and logarithmic functions. */
 double exp (double);
+double expm1 (double);
 double log (double);
+double log1p (double);
+double log2 (double);
+double log10 (double);
 
 /* Power functions. */
 double pow (double, double);

jerry-libm/jerry-libm-internal.h

@@ -89,7 +89,11 @@ double sin (double x);
 double tan (double x);
 
 double exp (double x);
+double expm1 (double x);
 double log (double x);
+double log1p (double x);
+double log2 (double x);
+double log10 (double);
 
 double pow (double x, double y);
 double sqrt (double x);